Re: "Apple Cash Payment to Friend. Where is the money?"
We are all Apple users, just as you are, in the community here, so we have no access to your accounts or details in order to check.
The linked article below explains how your friend can access the money.
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Re: "Can I cancel the apple cash payment? If so, how do I do this?"
Yes.
Seems so: ie: as long as the transaction in still "pending", and the receiver hasn't accepted it.
Send and receive money with Apple Cash - Apple Support
Eg: says:
"If you sent a payment to someone and want to cancel it
In your Apple Cash transaction history, person-to-person payments appear with a name, phone number, or email address. If the transaction status says pending, the receiver hasn't accepted your payment yet, and you can cancel it.
Apple Cash person-to-person payments are like any other private transaction between two people, so only send and receive money with people you know."
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More info. if needed: See what to do: If you have an issue with an Apple Cash transaction - Apple Support
Apple Cash Support hub: Apple Cash - Official Apple Support